Lecture 13

Question 1

how does the contribution from fats and carbohydrates to total energy change with duration of exercise

Answer 1

over time you will end up using a higher proportion of fats compared to carbohydrates as energy source

Question 2

how is ATP formed from creatine phosphate

Answer 2

creatine phosphate gets split, phosphate is added onto ADP to produce ATP

Question 3

what happens to the creatine phosphate equation during recovery

Answer 3

will go the other way around to how it normally does during exercise

Question 4

in times of need if anaerobic glycolysis is not going fast enough how can ATP be produced from ADP

Answer 4

adenylate kinase can use two ADP to produce ATP and AMP

Question 5

what will happen to AMP if there is a lot circulating in your body

Answer 5

it will get broken down

it is good for short periods but pretty easy to lose it

Question 6

creatine kinase catalyses the reaction of producing ATP from creatine phosphate and ADP, where is some of this found

Answer 6

bound to mitochondrial membrane and to myofibrillar proteins

Question 7

where is creatine synthesised

Answer 7

in the kidneys and also the liver

Question 8

what is creatine synthesised from

Answer 8

amino acids, glycine, methionine and arginine

Question 9

what are food sources of creatine

Answer 9

from meat

Question 10

3 ways the body can get glucose to be used as a fuel

Answer 10

• comes from the breakdown (glycogenolysis) of glycogen in muscle
• from glucose released into blood stream from liver (glycogenolysis and gluconeogenesis)
• from gut absorption from meal into circulation via portal vein (passes by liver too)

Question 11

location and fuel source of glycolysis

Answer 11

location = cytosol

fuel = CHO (glycogen or glucose)

Question 12

what is the difference between glycolysis and glycogenolysis

Answer 12

glycolysis = catabolism of glucose (or Glucose-1-P) to pyruvate

glycogenolysis = removal of individual glucose (Glucose-1-P) units from glycogen

Question 13

NADH is produced during glycolysis, where does this then get used

Answer 13

in the electron transport chain

Question 14

what is needed to convert pyruvate to lactate and where does this come from

Answer 14

NAD+ from the electron transport chain can be used to convert pyruvate to lactate

Question 15

as exercise intensity increases (energy demand increases) what happens to the amount of NADH2 formed in comparison to the amount that is oxidised in the ETC

Answer 15

more NADH2 is formed than can be oxidised by the ETC

Question 16

what is special about the LDH enzyme and what does this mean in terms of the pyruvate and lactate reaction

Answer 16

it is bidirectional

the same enzyme is used to breakdown pyruvate to make lactate and the opposite reaction

Question 17

when does the pyruvate to lactate reaction occur in the opposite direction

Answer 17

during recovery

Question 18

what type of curve / increase of glycogen use will occur during higher intensity exercise fuelled by anaerobic glycolysis

Answer 18

requires exponential increase in glycogen use

Question 19

what affects where glucose will come from

Answer 19

how well fed you are

what you have done before

etc

Question 20

where is most of the stores of CHO in the body (stores are relatively small)

Answer 20

muscle ~300g

liver ~100g